It was later in timing than the R-2800 with the first experimental engine run in May of 1940 and the 5th production delivered in Dec of 1941. By the time you get the 9th R-2000 P&W has delivered a total of 1469 R-2800s of all types. This does not include Ford production.
It might or might not have been suitable as an upgrade for C-47s or PBYs but for most other aircraft the extra 150hp or so wasn't going to make a big difference.

Military power at 16,000ft was 1100hp compared to 1050hp at 13,200ft for some of the R-1830 two speed engines so altitude performance wasn't that much better. Very late R-1830s (1350 hp for take-off) could make 1100hp at 13,750ft.

It might have been better getting transports or flying boats into the air but actual performance difference once in the air was going to minimal as might be expected from a 9.3% increase in displacement.